It was meant to be Hollywood's attempt at stealing a march on President Barack Obama's offer to reach out a hand to Iran - an ambassadorial trip to a country where it is reviled as decadent and accused of depicting Iran as hostile and backward.

If the august group - including American Beauty star Annette Bening, and Field of Dreams director Phil Robinson - thought their arrival in Tehran would be greeted in a spirit of peace and harmony, they had underestimated the pent-up anger of President Mahmoud Ahmadinejad's staunchly anti-western government.

Ahmadinejad's arts adviser, Javad Shamghadri, dashed hopes that the attempt at cultural detente would pass off smoothly when he demanded that the nine-strong delegation apologise for Hollywood's perceived past sins if they wanted to meet leading figures in Iran's film industry.

"[Iranian] cinema officials will only have the right to have official sessions with ... Hollywood movie-makers when they apologise to the Iranians for their 30 years of insults and slanders," Shamghadri told the news agency ISNA. "The Iranian people and our revolution have been repeatedly unjustly attacked by Hollywood. We will believe Obama's policy of change when we see change in Hollywood too, and if Hollywood wants to correct its behaviour towards Iranian people and Islamic culture then they have to officially apologise."

The demand for an apology echoed similar comments from Ahmadinejad, who has said Washington should admit past misdeeds as a condition for direct talks between the US and Iran.

It came as the group - which also included Sid Ganis, president of the Academy of Motion Picture Arts and Sciences, William Horberg, producer of The Kite Runner, and Alfre Woodard, who acted in Desperate Housewives - began a charm offensive billed as a "creative exchange" but clearly aimed at bridging a gulf of mutual misunderstanding.

The delegation was invited to Iran by Khane Cinema (Cinema House), the country's biggest film group, which is under the authority of the ministry of culture and Islamic guidance. It is scheduled to hold training workshops on acting, directing, documentary-making and other aspects of the business as well as tour the facilities of the state broadcaster, IRIB. Meetings have been promised with Majid Majidi and Ebrahim Hatamikia, two local directors in good standing with the theocratic government.

The visit bucks a recent trend of Iran discouraging cultural and academic exchanges with the US on the grounds that they could be used to foment a "velvet revolution" against the Islamic regime. An American women's badminton team was denied entry last month despite having been invited to play in a tournament.

That the Hollywood celebrities were granted visas suggests the government wants to alter the way it is depicted and undermines claims by the academy's communication director, Leslie Unger, that the visit had "no political agenda".

"The presence of the delegation might be an opportunity for showing the real image of Iran against the recent stream of anti-Iranian movies produced in Hollywood in which they try to show a bellicose, militaristic image of the country," wrote the newspaper Etemaad. "These well-known cinema figures can take a new genuine dynamic image of contemporary Iran."

Officials claim the country has suffered deliberate and systematic misrepresentation by Hollywood, which they often accuse of being controlled by pro-Zionist interests.

Two years ago, Ahmadinejad's government condemned 300, a Warner Bros production about the battle between Greeks and Persians at Thermopylae in 480BC, as "psychological warfare" and complained to the UN that it subjected Iranians to racial stereotyping. More recently, it singled out The Wrestler, starring Mickey Rourke, which, among other things, included a wrestler called "the Ayatollah".

Mistrust of Hollywood also prompted Ahmadinejad to decline a request by Oliver Stone, the director of JFK, to film a documentary about him. Ahmadinejad's advisers described Stone as "part of the Great Satan", despite his renowned leftwing sympathies and a track record of making documentaries about Fidel Castro and Yasser Arafat.

The hostile official view clashes with that of many ordinary Iranians, who eagerly watch Hollywood productions on pirated DVDs and on ostensibly illegal satellite channels. Hollywood films are also shown on state television but are censored for scenes deemed offensive to Islamic mores.

Offenders

International films that angered Iran

The Wrestler Caused offence when its main character, Mickey Rourke, smashed a pole carrying Iran's national flag across his knee. It also featured a wrestler called the Ayatollah - apparently after Iran's religious rulers - who wore a skimpy leotard in the country's colours.

The Stoning of Soraya M A woman is stoned to death under Iran's sharia law after being convicted of adultery.

Alexander The 2004 biopic about Alexander the Great, directed by Oliver Stone, was criticised for its sympathetic portrayal of the ancient Macedonian king, whom Iranians blame for the destruction of Persepolis in 330BC.

Body of Lies A 2008 Ridley Scott film in which Iranian actress Golshifteh Farahani's hair is shown.

Not Without My Daughter A 1991 film depicting the escape of a real-life American, Betty Mahmoody, from Iran. The government condemned it as projecting a negative image and banned the book on which it is based.